Paladin. They will add him in the expansion, I am sure. They already have an model with some animations (Tyrael).
Necro? There is an mini-quest in act II with Necro and his poision nova + we have bone-shield. They will add him too 99%.
I have 60s of everything but DH. For higher MP and ubers I like my barb. For speed on mp1 I like my monk, I liked my witch doctor until I discovered tempest rush on the monk, and haven't looked back at my witch doctor. Wizard is too slow for me, I like to dps on the move.
Still barb. Leveled 2 of them (well 4, really, but 2 didn't make it to 60) to 60 hardcore, with one of them dying in the crypts in Act1 and my current one farming to get ready for Act2. I don't like monk and I'm meh on DH/Wiz, but I have never touched a witch doctor. Probably never will.